Trouble with Kicad PPA install

When trying to install Kicad 5.0.2 from PPA, as recommended in 18.04, with:

sudo add-apt-repository ppa:js-reynaud/kicad-5
sudo apt update
sudo apt install kicad

I see strange effects, none of which are discussed at the Launchpad page.

• "Help/Getting started" gives an error. It is only available after running sudo apt install kicad-doc-en.

• After that install, it will open the file manager with the file marked, but not Firefox as expected. How can I change that? The page opens fine by double-clicking it in the file manager.

• The command sudo apt install kicad-libraries should install the symbol-, template- and footprint- libs. It did something, but they did not appear in the program. For example "File/New/Project from Template..." was empty. The templates appeared only after I installed sudo apt install kicad-templates

• After sudo apt install kicad-demo they can not be seen anywhere in the GUI. After a search I found them in /usr/share/kicad/demos. Is one really supposed to sudo copy them to the home directory and change all file permissions?

I crosschecked the Windows download for V5.0.3. There, everything installed, fully configured and ready to go. Why not in my Ubuntu? Tests were done on a fresh installation of Xubuntu 18.04.